Pressure-driven reciprocating tool.



A. PALMROS.

PRESSURE DRIVEN REGIPROOATING TOOL.

APPLICATION FILED APR. 4,1908.

Patentedoct. 12, 1909.

2 sums-sum 1.

GJM

A. PALMROS. PRESSURE DRIVEN REGIPBOGATING TOOL.

APPLICATION FILED APR.4, 1908.

937,009, Patented Oct. 12, 1909.

2 SHEETS-SHEET 2.

Mm ii? UNrrE "STATES PATENT OFFICE. 4

annxamma rammos or SYRACUSE, new YORK, assrenon TO THE rnnumnnnormc MACHINE COMPANY, orsrimcnsn, NEW max, A CORPORATION or NEW YORK.

rnnssuim-nmvnn REGIPROCATING TOOL.

Original application flled- November 25, 1905, Serial No. 289,127. Divided and this application filed April 4, 1908. .Serial No. 425,189;

To all whom 'it may concern.

, Be it known that I, ALEXANDER; PALMROS, acitizen' of Finland, and, resident of Syracuse, in the county of Onondaga, and State of New York,-*haveinvnted certain new and useful Improvements in Pressure-Driven Reciprocating Tools, of which the following is a specification.

Tl'llS application is a division of my application filed November 25, 1905, Serial N 0.-

stroke of the driven piston, is released and permitted to react upon the driven piston to drive it forward and deliverthe working stroke. One of the methods disclosed in my; said application for establishing retracting influence is by arranging for the expulsion of the body of driving a1r after completion of the working stroke and as the driving piston follows it forward and to admit air forward of the driven piston so that when the driving piston draws rearward, it will so far reduce the pressure in rear of-the driven piston as to permit the pressure medium in front of it to drive the driven piston backward.

The object of my present invention is to develop a more effective force in front of the driven piston tor the purpose of driving it rearward, and to these ends my present invention consists in supplying to t e space in front of the driven piston, a portion of the l'llllu pressure that was utilized to drive the driven piston forward so that as soon as a condition is developed in rear ofthe driven piston which will make the retracting pressure effective, said driven piston will be retracted positively and prom tly and be in a position to receive the next orward driving stroke to the best advantage.

According to another aspect, my present invention consists in trapping or confining Specification of Letters Patent.

Patented Oct. 12, 1909.

a portion of the actuating ressure medium in a pressure driven tool, w ile said medium is still at an effective density, and thereafter releasing said ressure medium against the forward face 0 the piston, after suitable reduction of the pressure on its driving face.

' My present invention further consists in certain features of construction whereby the severalobjects of, my invention are attained.

In the accompanying drawings, Figure l is a side elevation of an electropneumatic coal mining machine in which my present invention is embodied. by way of illustration; Fig. 2 is a vertical longitudinal section of the machine shown in Fig. 1, in the plane of the axis of the cylinder; Fig. 3 is a transverse section on the line 3-3, Figs. 1 and 2;

Figs. 4, 5 and 6 are longitudinal sections of the working cylinder and storing chamber in the plane of their axes, showing the pistons and the valve in different relative positio'ns; Fig. 7 is an axial section of the storage chamber and its valve taken in a plane at right angles to the lane of the sections shown in Figs. 4, 5 an 6.

1 represents the motor housing and 2 the piston housing or cylinder of an electropneumatic coal mining machine of the type selected for illustration of my present invention, which machine is usually mounted upon wlieels 3'and is provided with controlling handles 4 and current controlling switch 5. ,As these parts have no special connection with my present invention, they need not be furtherdescribed here.

. By referring to Fig. 2 it will be seen that the cylinder 2 contains a driven piston 6 whose rod 7 is designed to receive and carry-a suitable bit an a manner well known to those skilled in the art. In the type of machine selected for illustration of my inventlon, the piston 6 is acted upon expansivel by a body of air which is compressed by'ti ie retracting stroke of a drivin piston '8 which is housed in the same cylin er with SUED istons 8 and 6,

to a position between the ends of said bypass. During the retracting stroke of the piston 8 the piston 6 is also moved rearward by what we may term, the suction of the piston 8, that-is to say by atmospheric or other pressure actin upon the forward face of piston 6 simu taneously with the rarefaction of air between the pistons due to the rearward movement of piston 8 from the position shown in Fig. 6. For some purposes it will be sufficient, for retracting piston 6, to simply admit atmospheric air in front of said piston as the piston 8 moves rearward. But according to my present invention, I desire to secure a more positive retracting movement of the piston 6 than is attainableby the mere admission of atmospheric air in front of said piston at the time the air is being rarefied behind it; for which purpose, I provide means such as a valve housing 11 the two ends of which act as a single stora e space by reason of their communication hrough by -pass 11 (see particularly Fig, 7 for recelving a portion of the ressure medium (see Fig. 5) which drove t e piston 6 forward (Figs. 2 and 4) on its preceding stroke, and delivering (Fig. 6) it in front of said piston 6 at the time when it is desired to drive said piston rearward. For this purpose, housing .11 communicates through a port 12 with the cylinder 2 at a point that is in rear of piston 6 when the latter reaches its forward limit (Fig. 5), and also through a port 13 at a point forward of the forward limit of said piston 6, so that the driving pressure meium for the piston 6 may pass into.the housing 11 after the piston has received the necessary forward impulse and pass from said housing in front of the piston (Fig. 6); in other words, the housing forms a by-pass around the driven piston at the forward end of the cylinder.

To time the dellvery of the pressure medium from the housing 11 to the front face of the piston 6, said housing is rovided with a valve 14 controlled by a va ve stem 15, which is moved in one-direction by a spring 16 and in the other direction by a constantly rotating cam 17. While the piston 6 controls the port 12 of housing 11, it is preferable to have the valve 14 so positioned that it will regulate the opening-of said port. It is also preferable to have the valve l'control an exhaust port 18 (Fig. 4) which discharges into atmosphere at 19. The cam 17 "may be conveniently mounted upon the shaft 20 of the motor gear so that it rotates constantly. It is so designed that it will move valve 14 to the positionshown in Fig. 5 immediately after the piston 6 reaches its A forward limit, and hold it there nntil'piston 8 reaches its forward limit, when the housing 11 will have been charged with air under considerable pressure. Then'cam 17 moves valve 14 to close the port 12 and the exhaust port 18 and open port 13 (Fig. 6), which occurs-at the time piston 8 starts rearward. This releases the pressure medium in the forward end of housing 11 through bypass 11 and port 13 to the space in front of the piston 6 and drives the latter reaward, as air is exhausted behind it, with much eater force than if atmosphere alone were epended upon. As soon as the retraction is complete or has developed sufficiently to insure completion by the momentum of the parts, cam 17 moves valve 14 to an intermediate position (Fig. 4), at which it opens the exhaust 18-19, so as to avoid resistance to the forward movement of piston 6.

The rod'15 is not'connected directly with the cam, but for convenience is connected to a lever 21, fulcrumed at 22, which is in turn brought under the influence of the cam through the medium of-the push rod 23. As these details are not of the essence of my invention, they mayobviously be modified at will and according to circumstances.

It is to be understood that the piston 8 is constantly reciprocated through its rod 8 by ower received from any suitable source, as or instance, an electric motor located in the motor housing 1. I do not limit myself, however, to any specific means for imparting reciprocation to the piston 8.

Having thus described my invention, what I claimasnew therein, and desire to secure by-Letters Patent is:

1. A percussion implement having a suitable, housed pressure-driven piston receiving a pressure-medium on one face to develop a pulsation therein, and automatically controlledmeans for conducting a portion of the pressure medium which developed the pulsation, to the opposite face of the piston to cause retractionof the piston.

2. A- percussion im lement having a suitably housed pressureriven piston receiving a pressure medium on one face to develop a pulsation therein, and means including a port controlled by the piston, passing a portion of the pressure medium, after partial expenditureof its energy, to the opposite face of the piston, to cause retraction of the piston.

ably housed pressuredriven piston receiving a pressure medium on one face to develop a pulsation therein, and means trapping a portion of the driving pressure medium and thereafter releasing it against the forward face of the piston.

4. The combination of suitably housed driving and driven pistons having opposed faces; means whereby the driving piston compresses a fluid on its rear face on one stroke, and the fluid under pressure thus developed is delivered between the opposed faces of the pistons to develop a pulsation in 3. A percussion implement having a suitbination of suitably housed driving and driven pistons of which the driving piston exerts retracting influence over the driven piston, in additionto developing the projectin force therefor, and means, independent of the driving piston, delivering a fluid medium under pressure, forward of the driven piston wh1le the driving piston is exertin its retracting influence.

6. n a fluid pressure driven tool the combination of suitably housed driving and driven pistons of which the driving piston exerts retracting. influence over the driven piston, in addition to developing the projecting force therefor, and means, trapping a portion of the pressure medium, during the forward stroke and delivering a fluid medium under pressure, forward of the driven piston while the driving piston is exerting its retracting influence.

7. The combination of suitably housed driving and driven-pistons of which the driving piston develops pressure in a fluid on its rearward stroke, means delivering said fluid under pressure to the rear faceof the driven piston to develop a forwardimpulse therein, a chamber into which. fluid driv- -ing medium is forced by the forward stroke of the driving piston, and means delivering the pressure medium from .said chamber to the space in front of. the driven piston to'exert retracting influence 'on said driven piston.

8. In a fluid pressure driven tool the combination of suitably housed driving and.

driven pistons "of which the 1 driving (piston exerts retracting influence over the riven piston, in additlon' to developing the pro eeting 'force therefor, an exhaust port openmg communication with the space in front of the driven pistonduring its forward stroke, and meansjndependent of the driv- V combination of a ing piston delivering a fluid mediumunder pressure, forward of the driven piston while the driving piston is exerting its retracting influence. I

9. In a fluid pressure driven tool the combination of the driven piston and means receiving a portion of thepressure medium delivered to the rear face of said piston for driving it forward, and ommunicating the same to the forward face driving it rearward.

10. In a fluid pressure driven tool the piston receiving a fluid under pressure on its rear face to drive it forward, and means receiving a portion of the pressure medium as the piston nears its forward limit, and communicating the saine to the forward face of said piston for driving it rearward.

f said piston for 11. The combination of thesuitably housed driven piston, the valve chamber communicating with the housing of said piston at a point in rear of the forward limit of the piston and also at a point forward of said imit, whereby said valve chamber receives a portion of the driving pressure medium, and a valve controlling the delivery of said pressure medium to the cylinder forward of said piston.

12. The combination of thesuitably housed driven piston, the valve chamber communicating with the housing of said piston at a point in rear of .the forward limit said limit, whereby said valve chamber receives a portion of the driving pressure medium, and a valve controlling the delivery of said ressure medium to the cylinder forward 0 said piston, said valve also controllin said communication in rear of said li'mltand closing the same till the driven piston has passed.

13. In a fluid pressure driven tool, the combination .of the cylinder, the driven piston therein, the valve chamber having communication with the cylinder ata point in rear of the forward limit of the iston and also at a point forward of the said limit, and having an exhaust port; and a valve controlling said communications and exhaust port said valve opening the cylinder to exhaust during the forward stroke of'the piston, admitting driving pressure fluid to the chamber from the cylinder in rear of the driven piston, and then delivering said pressure fluid to the cylinder forward of said piston. I j x 14. In a fluid pressure driven tool the combination of suitably housed compressin and'driven pistons, at one stroke of whie the compressing piston exhausts the air behind the driven piston and compresses a fluid medium, while at the other stroke, the

riven piston receives the medium thus compressed and is driven forward by the same, and a chamber, communicating with the ing a portion of the pressure medium used to drive the driven piston forward, and dethe driven plston todrive the latter rearof the same by the retracting stroke of the compressing iston.

15. In a uid ressure driven tool, the combination of suitably housed driving and driven pistons, the motor actuating the driving piston, thechamber receiving driving pressure medium from the rear of driven piston'and supplying it to the front thereof, to drive itrearward, a valve in said chamber i for opening and closing the communications i between the pistonhousing and the chamber,

of the piston and also at a point forward of award, as the air is exhausted from the rear.

housing both forward and rearward of the forward limit of the driven piston, receiv-,

livering said pressure medium forward of &

ing piston, a cylinder in which said piston works and inwhich it is subjected to fluid ressure on its rear face to develop-its working stroke, and a chamber having a. port through which it communicates with the cylinder and receives fluid under pressure therefrom, and having a port communicating with, and returning said fluid under pressure to the forward face of saidpiston,

to drive it rearward.

17. In a fluid-pressure driven tool, a working piston, a' cylinder in which said piston works and in which it is subjected to fluid pressure on its rear face to drive it forward and develop its working stroke, and a chamber having suitably controlled ports thrbugh which it communicates with said cylinder, both in'rear and forward of the said piston, and through which it receives therefrom, under pressure, a part of the fluid that drives the piston forward and returns said fluid under pressure to the forward face of said piston to drive it rearward.

18. In a fluid-pressure driven tool,aworking piston,a cylinder in which said piston works and in which it is subjected to fluld pressure on its rear face to drive it forward and develop its working stroke, and a chamber havingsuitably controlled ports communicating with said cylinder, both in front and in rear of the forward limit of said piston, and receiving fluid under pressure from said cylinder in rear of said piston, and returning said fluid under pressure to said cylinder, forward of said iston, to drivethe piston rearward; means eing provided to time the opening of such communications.

19. In a'fluid-pressure driven tool, a fluidpressure driven working piston, a c linder in which said piston works and inwhich it is subjected on its rear face to the expansive action of the fluid pressure mediunnto drive it forward and develop its working stroke, a

chamber for storing thefluid medium under pressure, "having suitably controlled ports communicating with said cylinder, through which it receives fluid medium under pressure therefrom, and returns said fluid under pressure to the forward face of said working piston to driveit rearward, and a suitably housed pressure-developing piston, supply-,

ing said fluid-medium under pressure.

'20; In a fluid-pressure driven tool, a fluidressure driven working piston, acylinder 111 which said'piston works and in which it is subjected 011 its rear face to the expansive action. of the fluid pressure medium,-to drive it forward and develop its working stroke. a

cliamber for storing the fluid medium under pressure, having suitably controlled 2 ports e mugiicating w t ai I lin enithr ugh which-It receives fluid" medluin'underpres cylinder supplying said e-saooo sure-therefrom, and returns said fluid under pressure to the'forward endof said working piston to drive. it rearward, and asuitably housed pressure-developing piston, supplying'said fluid-medium under pressure compressing-the pressure medium on one stroke and on the other stroke forcing said medium, under pressure, into-the storage chamber.

21. In a fluid-pressure-driven tool, a fluidpressure driven working piston, a cylinder in which said piston works andin which it is subjected on its rear face to the expansive action of the fluid pressure medium,'to drive it forward and develop itsworkin stroke, a chamber for storing the fluid me ium un- :der pressure, having suitably controlled ports communicating with said cylinder, through which it receives fluid-medium under pressure from said cylinder, and returns said fluid under pressure to the forward end of said working pistonto drive it rearward,

and a pressure-developin piston also in said fluid-medium under pressure compressing the pressure medium and releasing it into the space'between the pistons on one stroke and on-the other stroke forcing a portion of said medium, under pressure, into'the storage chamber. 22. In a fluid-pressure driven tool, a fluidpressure driven working piston, a cylinder in which said piston works and in which it is subjected to fluid pressure on its rear face to drive it forward and develop its workin stroke, a chamber communicating with sai cylinder, receiving fluid under pressure therefrom,-and returning said fluid under pressure to the forward face of said piston to drive it rearward, a motor-driven compressing'piston also working in said cylinder, compressing a charge of fluid on its rearward stroke, there being means for delivering said charge under pressure thus developed, to the space between the pistons, whereby it drives the pressure-driven piston forward byits expansion, and said compressing, pistonthereafter following the pressure-driven pistonforward, to introduce a new charge in rear of said compressing piston and displace pressure medium from between the pistons into the chamber. 23. In apparatus of the class described, the combination with a reciprocatory gasdriven member, carrying atool, of a reciprocatory gas compressor associated therewith, and adapted to actuate said tool, and a positively driven associated valve-mechanlsm, adapted intermittently to open to the atmosphere, the space in advance of the driven member. 7

24. In apparatus of the class described, the combination with a reci rocatory gas-driven member, carrying a tool of a reciprocatory gas compressor associated 'therewith, and adapted toactuate said tool, anda positively driven associated valve-mechanism,adapted intermittently to open to the atmosphere, the space in advance of the driven member, and close such space during the retracting thereof.

25. A machine of the class described comprising a cylinder, tool-operating and fluidcompressing pistons independently reciprocable in said cylinder, said machine being provided with a by-pass permanently closed to the a-tmos here, and said machine also having ports or conducting compressed fluid from one side of one of said pistons to a space between said pistons."

26. A machine of the class described comprising a cylinder and a tool operating fluid pressure driven piston and a fluid compressing piston, independently reciprocable in said cylinder; said machine being provided with a bypass permanently closed to the atmosphere for conducting fluid from the space between the pistons to the space forward of the fluid pressure-driven piston, said machine also having ports for conducting compressed fluid from the compressing side of the compressing piston to a space between said pistons.

27. A machine of the class described'comprising a cylinder, tool-operating and fluidcompressing pistons independently reciprocable in said cylinder, said machine being provided'with a by-pass permanently closed to theatmosphere, said machine also having ports for conducting compressed fluid from one side of the fluid compressing piston to a v space between said pistons, and means for conducting fluid to the tool-operating piston for retracting the latter.

28. A machine of the class described comprising a casing provided with a cylinder, tool operating and fluid compressing pistons independently reciprocable therein, the-casing being provided with a by pass permanently closed to the atmosphere, said machine also having ports for conducting compressed fluid from one side of the compressing piston to a space between the latter piston and the tool operating piston, and means for conducting fluid to the tool-operating piston for retracting thelatter. g

29. A machine of the class described comprising'a cylinder, air compressing and tooloperating pistons, independently reciprocable in said cylinder, and by-passes at the respective ends of said cylinder, having ports by which they respectively communicate between the interpiston space and the outer faces of the twopistons.

respective ends of said cylinder, having ports by which they respectively communicate between the interpiston space and the outer faces of the two pistons, said cylinder also having at its respective ends, controlled ports communicating with atmosphere.

31. A machlne of the class described comprising a cylinder, air compressing and tooloperating pistons, independently reciprocable in said cylinder, and by-passes at the respective ends of said cylinder, having ports by which they respectively communicate between the interpiston space and the outer faces of the two pistons, said cylinder having air inlet and exhaust ports at its respective ends.

32-. A machine of the class described comprising a cylinder, a tool operating fluid pressure driven piston and a fluid compressing piston independently reciprocable in said cylinder, a valve housing secured to the cylinder, and provided with a by-pass and exhaust port, means located within the housing and adapted to prevent communication between the by-pass and exhaust port, the said by-pass being adapted to conduct fluid from the space between the pistons to the space forward of the fluid pressure-driven piston,

and means being provided for conducting trapping the air at the tool end of the percussion cylinder during the major portion of the return stroke of the tool, means for supplyin air to the opposite end of the tool cylint er and effecting the working stroke of the piston, and means for varying. the effective pressure of said latter air to limits above and below the normal pressure of the trapped air.

The foregoing specification signed at Syracuse, N. Y., U. S. A., this twenty-first day of'December, 1907.

ALEXANDER 'PALM'ROS.

In presence of twowitnesses:

JOHN E.- WOODRUFF, ELMER C. WARD. 

